The present invention relates to an electrical connector for a circuit board.
A conventional electrical connector for a circuit board has been disclosed in Patent Reference. In the electrical connector disclosed in Patent Reference, a bottom wall of a housing that holds a terminal passes through the housing to open downward. Further, the terminal is attached to the housing through the opening from below.
Patent Reference: Japanese Patent Publication No. 09-259979
In the electrical connector disclosed in Patent Reference, a receiving recess portion is formed in the housing between a sidewall and an opposed wall thereof. The receiving recess portion receives a mating connector. As described above, the receiving recess portion passes through the bottom wall to open downward.
The terminal is formed of a metal sheet maintaining a flat plate surface. The terminal has an attachment arm portion, a rising arm portion, and an upright arm portion. The attachment arm portion is pressed fit to an attachment hole that is formed in the sidewall of the housing from below. The rising arm portion is provided to be along the opposed wall of the receiving recess portion. The upright arm portion is formed along an inner wall face of the sidewall between the attachment arm portion and the rising arm portion.
The rising arm portion has a contact portion having a protrusion shape on an upper edge of an inner side edge thereof. The upright arm portion has a locking portion having a protrusion shape on an upper edge of an opposing inner side edge thereof. Further, a mating terminal that is attached to a supporting wall of a housing of the mating connector is received inside of the receiving recess portion and held between the contact portion and the locking portion. That is, the contact portion elastically contacts the mating terminal.
The locking portion enters a locking recess portion of the mating terminal. Accordingly, the mating connector is prevented from coming off. A locking protruding portion is formed on the upper edge of the opposed wall. The locking protruding portion is formed to protrude to cover the contact portion as an eave. The lower surface of the locking protruding portion is adjacent to face an upper edge of the contact portion.
When the mating connector is pulled out upward from the connector for a circuit board, the contact portion is pulled upward due to a contact pressure with the mating terminal. That is, the terminal is elastically deformed, so that the rising arm portion having the contact portion on the upper edge thereof is lifted upward. This tendency is especially remarkable when the mating connector is pulled out in an inclined state instead of being pulled out vertically upward. If no force is generated to stall the terminal, the terminal may come off or may be plastically deformed.
In the conventional connector disclosed in Patent Reference, the rising arm portion has the contact portion on the upper edge thereof. When the mating connector is pulled out to lift the rising arm portion upward, the contact portion immediately becomes adjacent to the lower surface of the locking protruding portion to prevent further lifting. Accordingly, the terminal is prevented form coming off.
In the conventional connector disclosed in Patent Reference, the locking protruding portion is provided. Accordingly, it is difficult to attach the terminal to the housing from above. Accordingly, as described above, the terminal is attached from below. As a result, the receiving recess portion opens downward. Accordingly, the terminal is attached from the opening of the housing that is formed to pass through the bottom wall. Thus, the housing regulates an upward movement of the attachment arm portion of the terminal.
With the structure mentioned above, it is possible to prevent the terminal from coming off when the mating connector is pulled out. That is, the terminal is effectively prevented from coming off due to the action of the locking protruding portion on the contact portion and the action of the housing on the attachment arm portion. However, a force that the contact portion receives from the locking protruding portion becomes a compressive force to the rise portion of the terminal. Accordingly, the rising arm portion may be buckled or plastically deformed.
Further, in Patent Reference, the bottom wall opens to pass through and the bottom arm portion that connects the rising arm portion and the upright arm portion is situated in the opening to directly face a circuit board. A gap is extremely small, and the bottom arm portion of the terminal may contact with an unnecessary portion due to a distortion caused by an influence factor such as heat of the circuit board or the like, thereby making contact unstable and not electrically preferable.
In view of the problems described above, an objective of the present invention is to provide an electrical connector for a circuit board in which a housing has a bottom wall so that a bottom arm portion of a terminal is not exposed downward. Accordingly, the terminal is not plastically deformed or does not come off due to an upward lifting of the terminal when a mating connector is pulled out even when the terminal is attached from above.
Further objects and advantages of the invention will be apparent from the following description of the invention.